Mechanical block system for tramways.



1). SAMAIA. MECHANICAL BLOCK SYSTEM FOR TRAMWAYS. APPLIOATION FILED JAN.17, 1910.

1,01 1,249. Patentd Dec. 12, 1911.

2 SHBETSSHEET 1.

I Witnesses s D. SAMAIA. MECHANICAL BLOCK SYSTEM FOR TRAMWAYS.

APPLIOATION FILED JAN.17. 1910.

1,01 1,249, Patented Dec. 12, 1911.

2 SHEETS-SHEET 2.

Inventor Witnessesi COLUMBIA PLANUGRAPH CO-,WAS}I1NGTON. u. c.

UNITED STATE PATEFT @FFIQE.

DINO SAMAIA, OF VENICE, ITALY.

MECHANICAL BLOCK SYSTEM FOR TBAMWAYS.

To all whom it may concern:

Be it known that I, DINO SAMAIA, a subject of the King of Italy, and resident of Venice, Italy, have invented a certain new and useful Mechanical Block System for Tramways, of which the following is a specification.

This invention relates to a mechanical block system for tramway lines, characterized by the disposition of four pedals, two for blocking and two for de-blocking, which are controlled by the agency of suitable elements for the operation of the signals.

In order to avoid that the track remains blocked at both sides, in the case when two vehicles drawn in opposite directions have arrived at the same instant on the respective locking pedals, the system has been conceived in such manner that at the one side the block pedal is disposed after the semaphore, while at the other side it is placed at some distance in advance of the semaphore. It results that on the simultaneous action of the two pedals, the signal to stop can only be seen by the driver of the vehicle operating the pedal disposed in advance of the semaphore, while the driver of the other vehiclehaving already gone beyond the semaphore can no longer see the signal to stop, and continues his journey.

In the accompanying drawing, given by way of example, Figure 1 is a general view of the system, and Fig. 2 is an enlarged view of the mechanism connected to the blocking pedal and Fig. 3 is an enlarged view of the mechanism connected to the semaphore and adapted to be operated on the operation of the pedals.

The system comprises four pedals a a, b b, that is, a block pedal a, and a de-blocking pedal 6 for the vehicles directed in the direction of the arrow 00, and two similar pedals a b, for the vehicles guided in the direction of the arrow y. Each of these pedals extends by its extremity 0 up to the level of the rail and is held normally in that position by a coiled spring d. To each pedal is fixed a bent lever e capable of oscillation about the pivot f. To the long arm of the levers of the pedals a a are attached cords g 9 connecting to levers 2' of the blocking mechanism, While similar cords h h are attached to the levers of the pedals Z) Z), connecting to the levers of the deblocking mechanism, which are controlled Specification of Letters Patent.

Application filed January 17, 1910.

Patented Dec. 12, 1911.

Serial No. 538,461.

by a spring Z. In a slot or recess m of the lever 70 is supported in a removable manner the pin a of the semaphore blade, when the latter is in the position indicating line clear as represented to the right of Fig. 1.

The operation is as follows :-Supposing at first that a vehicle is proceeding in the direction of the arrow :0, and it is necessary to block the line. Then the vehicle arrives on the pedal (4, this is depressed so that the lever e revolving on its pivot f is brought into the position indicated in dotted lines in Fig. 2 which causes a pull on the cord g. This pull is transmitted to the lever 1 and this is brought into the position indicated in dotted lines in Fig. 3, abutting in this way against the lever 70, which is thus pushed outward in such a way that the pin a comes out of the recess m. The semaphore being then no longer supported falls by its own weight into the horizontal position and gives in this way the signal of line blocked.

The tie-blocking is effected in the following way :The vehicle being moved in the direction of the arrow y, and the pedal 6 being depressed, a pull is exerted on the cord 71- and thence on the lever is which revolving on its pivot 2, is brought into the position indicated in dotted lines in Fig. 3, thus tightening the spring Z. This movement also results in the pin n being returned into the recess m where it is maintained by the spring 0 in such way that as soon as the vehicle has gone past the pedal 6 and consequently the pull exerted on the cord h has ceased, the spring 2' in relaxing brings back the lever 70 to the initial position thus bringing the recess at under the pin a and consequently raising the semaphore blade. In this way the signal line clear is again displayed.

It is to be understood that the invention is not limited to the arrangement hereinbefore described as modifications can be introduced for the application of the device to railways, without departing from the invention.

What I claim as my invention and desire to secure by Letters Patent is A mechanical block system comprising semaphores, blocking and ole-blocking pedals, pivoted levers operated by said pedals, mechanisms placing and retaining the semaphores in the off position when the deblocking pedals are operated, each of said mechanisms comprising a pivotally mounted lever, a spring acting on said lever, a lever In testimony whereof I have hereunto having a recess pivoted to said lever,aspring signed my name to this specification in the 10 connecting the said levers together, a pin on presence of two subscribing witnesses.

each semaphore, said pin being adapted to engage with the recess, mechanisms releasing DIN-O SAMAIA' the semaphores when the blocking pedals are Witnesses:

operated, and means connecting the said MENGOZZILI,

mechanisms to the pedals. ALEX. THAYER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

